The present application has for an object a ready-to-use agent for coloring keratin fibers, for example silk, wool or hair and particularly human hair, said agent containing (i) a heterocyclic hydrazone derivative, (ii) a —CH-active compound and (iii) an oxidant and furthermore a multicomponent kit and a method for coloring keratin fibers by use of said colorant.
Hair colorants are divided mainly into the groups of oxidation colorants and tinting agents, depending on the starting hair to be colored and the desired result. Oxidation colorants are eminently suited for covering large gray areas, the oxidation colorants used for gray areas of up to 50% are usually referred to as oxidative tinting agents, whereas the oxidation colorants used for gray areas of more than 50% or for “brightening” are usually referred to as oxidative colorants. Direct dyes are contained primarily in non-oxidative colorants (tinting agents). Because of their small molecular size, some direct dyes, for example nitro dyes, can penetrate into the hair and dye it directly, at least in the outer regions. Such tinting is very gentle to the hair and as a rule can withstand 6 to 8 hair washings. Direct dyes are frequently used also in oxidative colorants for producing certain shades or to intensify the color.
DE-A 1 922 400 discloses the use of hydrazones for coloring keratin fibers. These colorants, however, cannot meet the requirements placed on colorants in every respect, particularly as regards the luster and intensity of the colorations.